Shapefest - A massive library of 3D shapes for everything!
Wannathis - 3d illustrations and freebies
Craftwork - A collection of User Interface resources made by Craftwork
ccclaymoji - A fun little tool to make emojis that have a fun 3D-like effect.
Screenspace - ScreenSpace empowers app companies to showcase their products with the power of 3D device videos.
Khagwal 3D Illustration Library - Free 3D illustration library for web & mobile app designers